5 Signs You Need to Replace Your Microwave

Of all the appliances (large or small) in your kitchen, the microwave tends to have the shortest lifespan — around nine years or so. The good news? The new ones on the market are relatively inexpensive and you can get a decent one for less than $100.

How will you know if it's time to get a new one? Look for any of these five signs.

1. You hear loud noises while it's cooking.

That buzzing or banging you've been hearing lately? Yeah, that's not normal. If you peek inside and see that your plate is hitting the walls of the microwave or the turntable is off its base, either of those things could be the culprit. Try cleaning and reassembling the wheel and turntable.

If the plate is spinning just fine, look to see if there's splattered food in the vents covering the blade. If there is, give the inside of the microwave a good clean.

Once you've checked both of those things and before you nuke anything else, give your microwave a test run: Put a mug of water in and zap it for 10 seconds. If you're still hearing any sort of non-typical microwave noise, that's a sign of a defective power diode, magnetron, or high-voltage capacitor (those are all real things!), and you should get a new microwave.

2. It takes forever just to reheat lunch.

Every microwave has different cooking speeds and power, but if you notice that your bowl of soup's typical go-around doesn't seem to cut it anymore, the magnetron that controls all the microwave radiation is probably starting to fail. To check how well (or not well) your microwave is working, try that mug test again — this time for two minutes on high. By the time the buzzer goes off, your water should be steaming hot and ready for tea. If it's anything less, the machine isn't in its best shape.

3. You smell smoke or see fire.

Smoke, sparks, or fire are all signs that you need to stop using your microwave. Immediately. If there's a fire, wait for the fire to suffocate itself entirely before you open the door. Then assess: Did you accidentally reheat last night's Chinese food in that container with the metal handle? (You know better than that!) If you were following proper microwave protocol and it's not an issue with your food's vessel, do not wait for things to cool off and try again — the electrical components within the machine are failing and you should replace it. Also, unplug the microwave!

4. It runs for a few seconds, and then stops.

It can be easy to think that because it's still semi-functioning, this is just a minor issue. But the truth is that this can be caused by myriad of problems, including a big one involving the voltage transformer. Instead of hitting the "add 30 seconds" button every three seconds, hit the store.

5. The door won't fully close — or stay closed.

The point of a good seal on a microwave is to keep all those microwaves contained to a small space. So if any part of the door or frame on your machine is broken, cracked, or not suctioning properly, you're going to need to replace the unit.